The two sides are set to negotiate again on Sunday

WASHINGTON—Republicans and lawyers for the woman accusing Supreme Court nominee Brett Kavanaugh of sexual assault when they were teenagers tentatively agreed to a Thursday hearing, according to two people familiar with the negotiations. The deal all but ensures a high-stakes showdown that could shape the makeup of the high court.

Republicans had earlier insisted that the hearing take place on Wednesday, and not Thursday as sought by bioscientist Christine Blasey Ford. Both sides plan to talk on Sunday to discuss additional...